Suchergebnisse

The age‐period‐cohort model is known to provide an excellent description of the temporal trends in lung cancer incidence and mortality. This analytic approach is extended to include the contribution of carcinogenesis models for smoking. Usefulness of this strategy is that it offers a way to temporally calibrate a model that is fitted to population data and it can be readily adopted for the consideration of many different models. In addition, it provides diagnostics that can suggest temporal limitations of a particular carcinogenesis model in describing population rates. Alternative carcinogenesis models can be embedded within this framework. The two‐stage clonal expansion model is implemented here. The model was used to estimate the impact of tobacco control after dissemination of knowledge of the harmful effects of cigarette smoking by comparing the observed number of lung cancer deaths to those expected if there had been no control compared to an ideal of complete control in 1965. Results indicate that 35.2% and 26.5% of lung cancer deaths that could have been avoided actually were for males and females, respectively.

Currently the Chinese government has adopted World Health Organization interim target-1 values as the national ambient air quality standards values. However, the population-based evidence was insufficient, especially for the oldest old (aged 80+). We evaluated the association of fine particulate matters (PM(2.5)) exposure and incidence of disability in activities of daily living (ADL) in 15 453 oldest old in 886 counties/cities in China from 2002 to 2014 using Cox model with penalized splines and competing risk models to evaluate the linear or non-linear association. After adjusting for potential confounders, a J-shaped association existed between PM(2.5) exposure with a threshold concentration of 33 μg/m(3), and incident disability in ADL. Above this threshold, the risk magnitude significantly increased with increase of PM(2.5) concentrations; compared to 33 μg/m(3), the hazard ratio ranged from 1.03 (1.00-1.06) at 40 μg/m(3) to 2.25 (1.54-3.29) at 110 μg/m(3). The risk magnitude was not significantly changed below this threshold. Each 10 μg/m(3) increase in PM(2.5) exposure corresponded to a 7.7% increase in the risk of disability in ADL (hazard ratio 1.077, 95% CI 1.051-1.104). Men, smokers, and participants with cognitive impairment might be more vulnerable to PM(2.5) exposure. The study provided limited population-based evidence for the oldest old and detected a threshold of 33 μg/m(3), and supported that reduction to current World Health Organization interim target-1value (35 μg/m(3)) and Chinese national ambient air quality standards (35 μg/m(3)) or lower may be associated with lower risk of disability in ADL.

The Wuhan Pre/Post-Natal Twin Birth Registry (WPTBR) is one of the largest twin birth registries with comprehensive medical information in China. It recruits women from the first trimester of pregnancy and their twins from birth. From January 2006 to May 2016, the total number of twins enrolled in WPTBR is 13,869 twin pairs (27,553 individuals). The WPTBR initiated the Wuhan Twin Birth Cohort (WTBC). The WTBC is a prospective cohort study carried out through incorporation of three samples. The first one comprises 6,920 twin pairs, and the second one, 6,949 twin pairs. Both are population-based samples linked to the WPTBR and include pre- and post-natal information from WPTBR. The second sample includes neonatal blood spots as well. Using a hospital-based approach, we recently developed a third sample with a target enrolment of 1,000 twin pairs and their mothers. These twins are invited, via their parents, to participate in a periodic health examination from the first trimester of pregnancy to 18 years. Biological samples are collected initially from the mother, including blood, urine, cord blood, cord, amniotic fluid, placenta, breast milk and meconium, and vaginal secretions, and later from the twins, including meconium, stool, urine, and blood. This article describes the design, recruitment, follow-up, data collection, and measures, as well as ongoing and planned analyses at the WTBC. The WTBC offers a unique opportunity to follow women from prenatal to postnatal, as well as follow-up of their twins. This cohort study will expand the understanding of genetic and environmental influences on pregnancy and twins' development in China.